What is the reason for choosing a circular shape for the sewer manhole cover instead of a square?

Manhole covers are made round for several reasons:

• A round shape prevents the cover from falling into the hole because the diameter is the same in all directions. Unlike a square, where the cover can be rotated diagonally and fall inside.
• The round shape evenly distributes the load, which increases strength and durability.
• A round cover is easier to move; it can be rolled on the surface.

Thus, the round shape ensures safety, convenience, and reliability in operation.